[OpenWrt-Devel] Issue with deferred GPIO probing on ar71xx/TL-WDR3600 under kernel 4.4

Heiner Kallweit hkallweit1 at gmail.com
Sun Apr 24 10:53:26 EDT 2016

Under 4.4 I get the following errors which do not occur under 4.1:

[    0.120197] MIPS: machine is TP-LINK TL-WDR3600/4300/4310
[    0.126234] unable to request GPIO18 for external LNA0
[    0.132811] unable to request GPIO19 for external LNA1

Reason is that gpio_request_one() in the following calls of
the board initialization code returns -EPROBE_DEFER now.

ath79_wmac_set_ext_lna_gpio(0, WDR4300_GPIO_EXTERNAL_LNA0);
ath79_wmac_set_ext_lna_gpio(1, WDR4300_GPIO_EXTERNAL_LNA1);

I'm not sure how to handle the situation that the board
initialization code wants to access resources which are not
available yet.
A driver could defer its loading in this case, but most
likely we don't have this option for the board initialization
openwrt-devel mailing list
openwrt-devel at lists.openwrt.org

More information about the openwrt-devel mailing list